TESTING/EIG/dget51.f(3)    Library Functions Manual    TESTING/EIG/dget51.f(3)

NAME
       TESTING/EIG/dget51.f

SYNOPSIS
   Functions/Subroutines
       subroutine dget51 (itype, n, a, lda, b, ldb, u, ldu, v, ldv, work,
           result)
           DGET51

Function/Subroutine Documentation
   subroutine dget51 (integer itype, integer n, double precision, dimension(
       lda, * ) a, integer lda, double precision, dimension( ldb, * ) b,
       integer ldb, double precision, dimension( ldu, * ) u, integer ldu,
       double precision, dimension( ldv, * ) v, integer ldv, double precision,
       dimension( * ) work, double precision result)
       DGET51

       Purpose:


                 DGET51  generally checks a decomposition of the form

                         A = U B V'

                 where ' means transpose and U and V are orthogonal.

                 Specifically, if ITYPE=1

                         RESULT = | A - U B V' | / ( |A| n ulp )

                 If ITYPE=2, then:

                         RESULT = | A - B | / ( |A| n ulp )

                 If ITYPE=3, then:

                         RESULT = | I - UU' | / ( n ulp )

       Parameters
           ITYPE

                     ITYPE is INTEGER
                     Specifies the type of tests to be performed.
                     =1: RESULT = | A - U B V' | / ( |A| n ulp )
                     =2: RESULT = | A - B | / ( |A| n ulp )
                     =3: RESULT = | I - UU' | / ( n ulp )

           N

                     N is INTEGER
                     The size of the matrix.  If it is zero, DGET51 does nothing.
                     It must be at least zero.

           A

                     A is DOUBLE PRECISION array, dimension (LDA, N)
                     The original (unfactored) matrix.

           LDA

                     LDA is INTEGER
                     The leading dimension of A.  It must be at least 1
                     and at least N.

           B

                     B is DOUBLE PRECISION array, dimension (LDB, N)
                     The factored matrix.

           LDB

                     LDB is INTEGER
                     The leading dimension of B.  It must be at least 1
                     and at least N.

           U

                     U is DOUBLE PRECISION array, dimension (LDU, N)
                     The orthogonal matrix on the left-hand side in the
                     decomposition.
                     Not referenced if ITYPE=2

           LDU

                     LDU is INTEGER
                     The leading dimension of U.  LDU must be at least N and
                     at least 1.

           V

                     V is DOUBLE PRECISION array, dimension (LDV, N)
                     The orthogonal matrix on the left-hand side in the
                     decomposition.
                     Not referenced if ITYPE=2

           LDV

                     LDV is INTEGER
                     The leading dimension of V.  LDV must be at least N and
                     at least 1.

           WORK

                     WORK is DOUBLE PRECISION array, dimension (2*N**2)

           RESULT

                     RESULT is DOUBLE PRECISION
                     The values computed by the test specified by ITYPE.  The
                     value is currently limited to 1/ulp, to avoid overflow.
                     Errors are flagged by RESULT=10/ulp.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 147 of file dget51.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0         TESTING/EIG/dget51.f(3)